1. La Potencia (Yoenis Cespedes): A perfect match of descriptor ("la potencia" is Spanish for "the power") and general cool-sounding name.
2. Bringer of Rain (Josh Donaldson): A good vaguely metal choice for a dude who fancies himself a resurrected Viking .
3. Flaco Fuerte (Chris Archer): "Skinny Strong Man" is as weird as it gets, but bonus points for alliteration.
4. Tsunami (Carlos Martinez): Natural disasters/weather events always make for good nicknames.
5. Tokki 2 (Joey Votto): "Tokki" is Korean for rabbit; the nickname comes via Votto's former Reds teammate, Shin-soo Choo. You can read the whole backstory here , and it's cute and funny enough that this moniker gets pretty high up.
6. Corey's Brother (Kyle Seager): Either Kyle has a fantastic sense of humor for a big brother, or he got tired of trying to think of something after 10 minutes. It can be both, I guess.
7. Wawindaji (Hunter Pence): "Wawindaji" is Swahili for "hunters." I don't know if Pence knows that his nickname is plural. Maybe it doesn't matter.
8. Pappo (Adam Jones): I don't know the story behind that one, but it's a cool-sounding name, at least.
9. All Rise (Aaron Judge): This one loses points because it's not a nickname; it's an appropriate pun to yell when Judge homers, but it's not a nickname. Case closed.
10. Codylove (Cody Bellinger): This is right where things start to go south, though "Codylove" would make for a good Swedish or Korean boy band name.
11. Stickman (Chris Sale): Points gained for accuracy and for being a nickname that I can sing to the tune of Soundgarden's "Spoonman", but points lost for being very lazy and something that no one would actually call Sale.
12. Big Kid (Bryce Harper): No one has ever called him this.
13. EE (Edwin Encarnacion): This is not a nickname. It's a contraction.
14. Yoyo (Yoan Moncada): Fine, sure, though "The Twinkie Kid" is right there.
15. Kiiiiid (Mike Trout): Why are there so many "I"s in this? At least he didn't go with the Millville Meteor.
16. El Koja (Adrian Beltre): Someone please explain this one to me.
17. Cruz (Giancarlo Stanton): This is not a good nickname, but Stanton is too imposing for one anyway. Honestly, he'd be a good choice for an alliterative physical landscape—"The Miami Mountain," or something like that.
18. Nado (Nolan Arenado): Please try harder.
19. KB (Kris Bryant): Please try harder.
20. Miggy (Miguel Cabrera): Please try harder.